GILZ-expressing DCs and antigen-specific response of CD4⁺ T lymphocytes. MoDCs were treated on day 5 with control (siC; □) or GILZ (siGILZ; ▪) siRNA and with DEX, IL-10, or medium. They were loaded with PPD, washed, and mixed with autologous CD4⁺ T lymphocytes on day 7. (A) Lymphocyte proliferation, determined by Pkh26 fluorescence intensity (1 representative experiment of 3). The mean (SEM) fraction of Pkh26^low CD4⁺ T lymphocytes in the 3 experiments is shown in the top right corner. Horizontal bars indicate Pkh26^low cells. (B) IFNγ production (mean ± SEM of 2 experiments). In the absence of PPD loading there was no proliferation and less than 250 pg/mL IFNγ. (C) CD34-DCs were treated on day 8 with control (□) or GILZ (▪) siRNA and with DEX, IL-10, or medium. On day 12, the DCs were mixed with allogeneic T lymphocytes at a 1:2 ratio. Proliferation is expressed as percentages of values for controls, to which no DEX or IL-10 was added to DCs. Results (mean ± SEM) are from 1 representative experiment of 2. Thymidine incorporation (mean ± SEM) by cells stimulated with control or GILZ siRNA-treated DCs, without DEX or IL-10 addition, was 21 984 ± 5 206 cpm and 31 842 ± 9 023 cpm, respectively. (D) MoDCs were nucleofected with pcDNA3 or pGILZ on day 6, loaded with PPD on day 7, and cocultured with Pkh26-labeled CD4⁺ T lymphocytes. T lymphocyte proliferation was determined 7 days later. Results are from 1 representative experiment of 6, in which the inhibition of proliferation with GILZ-expressing DCs was 50.3% ± 8.0% (mean ± SEM) compared with control DCs (P < .05).